Posted by Jacqueline Beggs, Kate Irvine, Ian Mell, Margaret Stanley, Laurence Jones, Mike Dodd, Mark Goddard, Andy Moffat, Gina Cavan, Helen Rawlinson, Luciana Luna, Panteha Daie, Stefan van der Esch, Laila Almulla

Want to improve the value of your home, reduce your stress levels, save on air-conditioning in summer and encourage birds into your garden? Trees can provide all of that, and often the larger the tree the larger the benefits.

The value of urban trees and green-spaces are many. A recent symposium drew together a diverse range of practitioners, researchers, policy makers, and planners – from New Zealand, South Africa and Mexico, to USA and Europe. There is a voracious appetite for sharing ideas and knowledge linking together social, environmental and economic strands to build resilient cities. Finding the sweet spot that balances potentially competing demands is a challenge, so the opportunity to exchange ideas and resources was fruitful.

Some emerging strands:

1. What are the social implications of greening cities? If adding trees increases property values, does this drive-out lower socio-economic groups? How can we make this more equitable so all sectors of community benefit? How do we best protect urban forests? Recent changes which removed blanket protection of urban trees in Auckland New Zealand potentially leaves socially deprived areas more vulnerable to losing trees. Detroit (Michigan, USA) was suggested as a city to watch as innovative, community based ventures turn urban collapse into urban renewal.
   

   Urban ‘development’ in Auckland (left) contrasts with urban renewal in Detroit (right)

2. How do we adequately measure less tangible benefits of urban green? Does it matter how frequently we visit? What contribution does the ecological quality or type of urban green make to our well-being?
   

   Don’t wait until this state for a break. Drawn by Fritz Ahlefeldt

   While policy and practice currently emphasise physical and mental benefits, people using urban parks and riverscapes also report feeling calm, relaxed, or more emotionally attached to the green space after being there. In today’s pressured lifestyles, such greenspaces provide invaluable “timeout”. Watch out for publication of Kate Irvine’s fascinating research in this area.

3. In times of austerity, we need to find new financial models for adding and maintaining urban green/open space. There are financial benefits: we know people are willing to pay more to live on a “green street”. Ian Mell’s research on blending practice and policy brought useful insights to better planning and implementation to improve the liveability of cities.
4. There are many citizen science projects where people can help to collect data that can be used to study biodiversity in urban areas. For example, in Auckland NZ there is a project collecting data on the distribution and abundance of a large endemic wood pigeon, while the treezilla project aims to make a monster map of trees in Britain.
5. Does new green infrastructure actually reduce biodiversity by replacing naturally rewilding areas with “manicured” green?
   

   The Atlanta Beltline converted disused railway tracks into 23-mile recreational greenway which is designed to integrate an evolving ecological landscape into the everyday lives of the city’s residents.

   The Atlanta beltline was used as an example of an innovative funding model for greenspace, while at the same time there was concern that it had resulted in loss of biodiversity. But is this an acceptable trade-off in some urban locations where biodiversity aspirations are unrealistic? How are we to manage competing demands on our green spaces? Perhaps it is time for ecologists to move beyond advocating primarily for native trees to enhance biodiversity, but instead incorporating non-native species if they tolerate future climates and pests.

   

   The London Wetland Centre welcomes about one million visitors a year of which 50,000 are school children to learn about wildlife and conservation in urban areas.

6. Around the world there are many exciting urban greening initiatives we can all learn from. GRaBS provides some excellent case studies which share experience and good practice on how to integrate climate change adaptation into urban and town planning. In addition, London has an extraordinarily successful wetlands centre, Paris has brought in legislation for green roofs on all new industrial buildings, Portland (Oregon, USA) offers “treebates” to residents planting trees in their gardens, and Manchester has a growing number of beehives on urban buildings and four UK cities have set up an experiment to assess how best to improve cities for wild pollinators. What is your city doing? We’d love to hear new initiatives from other countries.

The authors of this article all participated in a symposium on restoring urban ecosystem function at the World Conference on Ecological Restoration held in Manchester 26 August 2015.